Musannaf Ibn Abi Shayba 24:112

Marhum ibn Abd al-Aziz narrated to us, from Malik ibn Dinar, that he heard him saying: Salim ibn Abd Allah said: Umar ibn Abd al-Aziz said to me, "Write to me with the Sunnah of Umar." I said, "If you act according to what Umar acted upon, then you are better than Umar, for you do not have a time like the time of Umar, nor men like the men of Umar."